Pneumatic action for musical instruments



May 8. 1923- w. E. AUST PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS 2Sheng-sheet 1 @WML/Lf;

May. 8, 1923. 1,454,259 7, w. E. AUSTIN PNEUMATIC ACTIUKFOR Ml-ISIC'ALINSTRUMENTS F'vled `OC1.,.\ 5 1917 2 Shggtg-Shggt' 2 11 a 'ze' 6 f L E/5 @f w 2z* y l v 7% A? Z m ,2a/ 4 n :zZ/5 ai: M

S S Y w MM/f* BWM fpwf Patented May 8, 1923.

-UNITED STATES PATENT OFFICE.

WILLIS E. AUSTIN, OF MINNEAPOLIS, MINNESOTA; JOHN S. AUSTINADMINISTRATOR OF SAID WILLIS E. LLUSTIN, DECEASED.

PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS.

Application filed October 5, 1917.

with the use of bellows pneumatics or at-y tached diaphragms and therebyeliminate the trouble and annoyance arising from the use of such devicesand the expense and time required for renewing or replacing worn outparts.

A further object is to provide a pneumatic action for an instrument ofthis class constructed as a removable and separable unit, any number ofwhich may be assembled or arranged in a group or bank as required forthe size of the instrument to be operated,

. each unit being separately removable for examination or repairswithout disturbing the other units of the group, and each unit havingall of its moving parts retained in their respective positions in thedevice without the use of any permanent attaching means, whereby all ofsaid parts are conveniently accessible for insertion or removal.

The invention consists generally in various constructions andcombinations, all as hereinafter described and particularly pointed outin the claims. v

The present invention is a modification and adaptation for player pianosof the cssential features of the invention shown and described in myco-pending application, Serial No. 110,307,iiled July 20th, 1916, whichhas matured into Letters Patent No. 1,295,672, issued February 25, 1919.

In the accompanying drawings forming part lof this specification,

Figure l is a sectional view through a portion of the pneumatic actionof a piano player, to which in this instance I have applied myinvention,

Figure 2 is a similar view of one of the units of the action,illustrating the oscil.

lating plate or piston of the motor in its raised position for operatingthe mechanism to strike the strings of the piano,

Serial No. 194,864.

Figure 3 is a front elevation, partially in section, showing atransverse view of the motorv chamber and the loosely mounted disccontrolling the movement of a valve,

Figure 4 is a plan section, showing the position of the motor operatingarms with respect to the stickers leading to the hammer actions of thepiano,

Figure 5 is a. detail sectional view, illustrating the motor partsseparated,

Figure 6 is a detail sectional view on an enlarged scale of a modifiedconstruction of the disc casing,

Figure 7 is a plan view of the motor oscillating plate or piston.

in the drawings, 2 represents one of the notor frames, which is hereshown as of substantially rectangular shape, and provided with alongitudinally extending recess forming a chamber 4, having inclined orbeveled walls 6 extending across one end of the chamber (which forconvenience l term the forward end), and along two of the sides thereof,the bevel decreasing and vanishing at the other or rear end of thechamber. The chamber 4 is also preferably of greater depth towards itsforward end, and is open at one side, and a separable chamber section,or frame 8, is provided having a corresponding opening and formedinteriorly with a beveled wall 6a corresponding to the beveled wall 6 ofthe chamber 4.

A plate 8, provided with a flexible sheet 9 projecting beyond the edgesof the plate (see Figure 7), iits within the opening of the chamber.rlhe edge of the sheet 9, at one end of the plate, extends into a recess7, in the upper surface of the frame section 3, where it is held betweensaid section 3 and the edge of the motor frame 2. rlhe remaining portionof the edge of the sheet 9 extends into the recess formed between thebeveled wall 6 of the motor frame and the beveled wall 6a of the section3. The frame section 3 is secured to the motor frame 2 preferably bysuitable screws 10.` The part of the edge of the sheet 9 that lies inthe recess 7 forms a hinge upon which the plate 8 with the attachedsheet 9 oscillates, the edges of the sheet, except the part confined inthe recess 7, turnin in the groove or recess formed by the beveled walls6, 6, of the motor frame and section 3.

By taking out the screws 10 the section 3 may be readily removed, andthe oscil lating plate or piston 8 may be taken out of the chamber 4,for inspection or repairs, and may as readily be restored to position`and secured by putting back the screws 1l).

An operating bar 11 is Secured to the outer surface of the plate 8,preferabl outside of the sheet 9. This bar extends cownward and projectsforward beyond the wall of the motor frame, as illustrated in thedrawings. Each of the operating bars 11. is adapted to engage and move asticker bar 13, which, through devices well known in the construction ofa player piano, leads to means for operating the piano strikingmechanism.

Fach of the sticker bars, as here shown, is provided with an adjustablelug 12 which stands in the path of movement of the operating bar 11, sothat when said bar is moved from the position shown in the lower part ofFigure 1 to the position shown in the upper part of said figure, or inFigure 2, the corresponding sticker' bar will be operated in a mannerwell understood in instruments of this type. l. have shown in Figure 4 aseries of the sticker bars 13, and two of the operating bars 11,illustrating their relation to said sticker bars. It

will be understood that one of the motor units will be provided for eachsticker bar. and that the number of motor units required for anyinstrument will depend upon the number of sticker bars with which theparticular player piano is provided.

The rear portion of the motor frame has an upwardly extending,preferably rectangular, portion which I prefer to form as a separateblock 2, and which is secured to the motor frame 2, preferably by screws30, which pass through an overlying plate 29. through the block 2a, andinto the upper portion of the motor frame 2. This construction isclearly illustrated in Figure 5, in which the parts are shown separatedone from another.

An exhaust or vacuum trunk 14 extends across the forward portion of allof the motor frames. A vacuum is continuously maintained in this trunkby a suitable suction or pumping device (not shown).

I prefer to form the vacuum trunk 14 of substantially rectangular formin cross tion, with an inturned Hange 14n at its lower forward edge,adapted to be engaged b v a projection 2c on the upper forward edge ofthe motor frame 2. The vertical dimension of the exhaust trunk 14preferably corresponds, substantially, to the like dimension of theblock 2, formingr the upward rear projection on the motor frame, wherebythe forward wall of the block 2a and the rear wall of the vacuum trunk,when brought together, make a substantially close joint as inicated inFigures 1 and 2 and 4 of the drawings. After the parts of the motor unitare assembled. or brought into the relation indicated in Figures 1 and 2of the drawings, said motor units are secured to the vacuum trunk 14 bybeing placed side by side, as indicated in Figure 3 of the Ydrawings,with the projection 2 on each unit engaging the 'flange 14a. on thevacuum trunk. Screws are then inserted through opposing recesses 2b.formed in the walls of the blocks 2, the ends o l? said screws extendinginto the wall of the vacuum trunk 14, as illustrated in Figure 4 of thedrawings.

It will be understood that any desired number of groups of said motorunits may be arranged in a bank, one horizontal group bei ngarrangedaboveanother'.asillustratedin Figure il of the drawings, and that avacuum trunk 14 will be provided for each horizontal group of motorunits. lt will also be understood that in vertical arrangement the unitswill be offset, or break joints thereby permitting a close spacing ofthe sticker bars 13 as indicated in Figure 4, and proper engagementthereof b v the operating bars 11.

'lhe upper surface of the block 2a is provided with a chamber 22, whichconnects at one end with a passage 27 extending downward through theblock 2'd and the motor frame 2, and Ca'ninecting with the motor chamber4. The upper wall of the chamber 22 is preferal'lly formed by the plate29, and said plate is provided with a port 26. Beneath the port 26 andin line therewith .is a port 2? leading from the chamber 22 into achamber 24n preferably provided with a beveled lower wall 241. Thechamber 24'l is connected by a port 24 with the interior 0f the vacuumtrunk 14. Beneath the chamber 24 a recess 20 having a beveled Wall, anda central well or depression 17, the beveled wall of the recess 2()standing opposite the beveled wall of the chamber 24. Arranged in therecess 20 is a flexible sheet 18. having secured thereti') a disc 19,the d'1- anieter oi: which corresponds substantiallv t0 the diameter ofthe chamber 24u. A duet 16 leads from the well 17. below the disc 18,preferably extending horizontally, then vertically in the block 2, andthen 4horizontally to the rear of the block 2a, and communicating` witha duct 1G that is here, shown as extending across the vacuum trunk 14. Atube lil is connected with a port in the tracker bar (not shown) of theplayer plano over which the roll of perforated papel' passes. The tube15 also connects with the duet 16, as shown in Figure 2 of the drawings.The end ot' the duct 1Ga is preferably enlarged, so as to form a recessor smal chamber 1Gb from which a fine opening or ybleed-hole 25 extendsinto the vacuum trunk 14.

A valve 21. having downwardly extending guiding flanges 21, is arrangedin the chamber 22, beneath the port 26, with said guiding'flangesextending downward through the port 23 into the chamber 24a.

In Figure 6 I have shown the recess 2O cut or formed in the upper partof the frame 2, the flexible disc 18 being inserted therein by foldinginward its edges.

Operation.

It will be understood that in the operation of pneumatically actuatedplayer pianos, the piano is operated eachv time a perforation in theperforated sheet passes the corresponding controlling port or duct onthe tracker bar. In the device herein shown and described the tube 15,leading from the tracker bar, will be closedl or sealed so lone` as animperforate portion of the perforated sheet' is passing over thecorresponding port or duct. When a perforation passes over such port orduct air will be permitted to enter the corresponding tube 15, and passtherethrough 'and into the corresponding duct 16".

Assuming that the port on the tracker bar communicating with the tube 15of the motor unit, shown at the lower portion of Figure 1 of thedrawings, is closed or sealed, the parts will then stand in the positionshown in the lower part of Figure 1 of the drawings.' The suction fromthe vacuum or exhaust trunk 14l will create a vacuum in the well ordepression 17 beneath the iiexible disc 18, and also in the chamber 24a.The air from the depression 17 will be drawn into the vacuum trunk 14through the duct 16, the chamber 16h, and the bleed-hole 25, while theair from the chamber 24a will be exhausted through the port 24.Atmospheric pressure upon the valve 21 will hold it in its lowestposition, closing the port 23. Air will now enter the motor chamber 4,through the port 26, the chamber 22 and the passage 27, and theoscillating plate or piston 8 will stand in its lowermost position, withthe edge of the sheet 9 against the beveled wall 6L of the section 3. Assoon, however, as air is permitted to enter the tube 15, through thepassage of a perforation in the control sheet over the port in thetracker bar communicating with such tube 15, such air will pass freelythrough the duct 16 into the recess 17 beneath the flexible sheet 18,and the suction, from the vacuum trunk 14` will raise the valve 21,because the area of said valve is less than the area of the sheet 18,and the parts will now stand in the position shown in the upper part ofFigure 1, with the port 26 closed by the valve 21. The air will beexhausted from the motor chamber 4 through the passage 27, the chamber22, the port 23, the chamber 24a and the port- 24, and the oscillatingplate or piston 8 will instantly be thrown upward, from the positionshown in the lower part of Figure 1, to

the position shown in the upper part of Figure 1, and also shown inFigure 2. This movement of the oscillating plate or piston 8 will,through the operating bar 11, and the sticker bar 13 operate the strikermechanism of the piano. As soon as the passage of air to the tube is cutoff by an imperforate portion of the control sheet of the piano player,the air will be exhausted from the well or depression 17 through theduct 16, the chamber 16h, and the bleed-hole 25, and the valve 21 willdrop from the position shown in the upper part of Figure 1 of thedrawings to the position shown in the lower part of said gure. Air willthen pass freely through the port 26, the chamber 22 and the passage 27to the chamber 4 and the oscillating plate or piston 8 will immediatelydrop to the position shown in the lower part of Figure 1 in thedrawings. These operations will be repeated so long as the perforatedsheet is passed over the tracker bar.

It will be seen that I do away with the usual bellows-pneumatic in whichfiexible bellows walls are permanently secured to rigid wall. Suchfiexible walls are liable to become cracked and broken and are difficultof repair. In my device the flexible sheet 9 of the motor, and theflexible disc 18 below the valve 21, which are the only parts that areat all liable to need replacement, may be quickly removed and replaced,and every part of the entire device is readily accessible and removablefor inspection or repairs.

The motor chamber 4 is quite shallow and the air may be almost instantlyexhausted therefrom, thus producing a very quick, rapid upward movementof the movable plate or oscillating piston 8 and a correspondingly rapidmovement of the sticker bar that is moved by said piston.

From the foregoing description it will be noted that I am able toprovide a pneumatic action which will be positive and reliable in itsmovement, comparatively simple in construction and will dispenseentirely with attached diaphragms, bellows-pneumatic and the like.

I do not limit myself to the details of the construction herein shownand described, as the same may be varied in many particulars withoutdeparting from my invention.

I claim as my invention:

1. In a pneumatic action for musical instruments, the combination, witha motor chamber having an open wall, of a movable member arranged toclose the opening in said wall and provided with a fiexible sheetbearing to bear against the wall of said chamber, said flexible sheetbeing free and unattached except to the movable member, an operating barsecured to said movable member, and means for alternately exhausting theair from said chamber, and permitting it to re-enter therein.

In a pneumatic action for player pianos, the combination, with a motorchamber having an open Wall, of a movable member arranged to close theopening in said Wall and provided with a exible sheet pro-` jecting fromthe edges of said member, and disposed ,to bear against the Wall of saidchamber, said iexible sheet being free and unattached except to themovable member,

- a sticker operating bar secured to and pro- `iecting from said movablemember, an means for alternately exhausting the air from said chamberand permitting it to reenter therein.

3. In a pneumatic action for played pianos, the combination, with amotor chamber having an open wall, of an oscillating plate or pistonarranged to close said opening, and provided with a flexible sheetdisposed to bear against the Wall of said chamber, said flexible sheetbeing free and unattached except to the plate, an operating bar securedto said plate,v an exhaust trunk, and a valve controlled passagepermitting air to be exhausted irom said chamber by means of said trunk,and to re-enter said chamber, Whereby an oscillating movement of saidplate or piston is produced.

4. In a pneumatic action for player pianos, the combination, with amotor chamber, having an open wall. of a movable member arranged toclose the opening in said Wall and provided with a flexible sheetprojecting from the edgesof said member, said flexible sheet, at one endof the movable member, extending into a recess at the end of thechamber, and forming a hinge upon which said member may oscillate, therev maining portion of the edge of said sheet being disposed to bearagainst the wal] of said chamber, said sheet being free and unattachedexcept to the movable member, an operating bar secured to andlprojecting Vfrom said movable member, and means for alternatelyexhaustingr the air from said chamber and permitting it to re-entertherein.

5. In a pneumatic action for playerl pianos, the combination,\vith amotor chamber having an open wall, of a frame section secured to thewall of said chamber around said opening, a beveled recess being formedbetween the wallr of the chamber and the 'traine section across one endof the chamber and along each side thereof, said recess along the sidesof the chamber decreasing progressively and vanishing near the end ofthe chamber, a movable member arranged `to close the opening in saidwall and provided with a flexible sheet projecting from lthe edges ofsaid member, said flexible sheet, at one end ot' the movable member,extending into a recess at the end of the chamber and forming a hingeupon which said member may oscillate, the remaining portion f the edgeof said sheet being disposed in said beveled recess and disposed to bearagainst the walls thereof, said sheet being free and unattached exceptto the movable member.

In witness whereof, I haveV hereunto set my hand this 18th day ofSeptember 1917. WILLIS E. AUSTIN.

